1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
2. Department of Clinical Epidemiology and Biostatics, University of Ulsan college of Medicine, Asan Medical Center, Seoul, Republic of Korea.
3. Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.